I had a random thought today, triggered, by all things, by a short training on Reduce, Reuse, Recycle at work. This is the principle of first looking for the potential to not produce anything. Then to look for a new use for something old that has already been manufactured. And only then, as a final step, to recycle the thing.

I, and probably many other Homelabbers, have quite a bit of older hardware laying around. Hardware that’s still perfectly functional, but which is either too slow, or doesn’t support newer features etc. For me, that’s only two things, because I was a poor student until relatively recently. 😉. The first one not discussed here is a desktop from 2017 which I replaced in 2019. It is an AMD Ryzen 1700x. Still a powerful machine, but quite honestly: A bit more powerful and power hungry than my new many small and less powerful machines Homelab principle calls for.

The second complete machine is my old homeserver, build in early 2018 and replaced in early 2021. It has the following primary hardware:

  • AMD A10-9700E This APU has four physical cores and four threads. It is that generations low power desktop CPU, with a TDP of 35W.
  • MSI A320M PRO VD/S I mostly got this mainboard because it was cheap at the time. It boasts two RAM slots, Dual Channel and four SATA ports and supports a maximum of 64GB of RAM (see below)
  • Corsair VS350: I would have loved to link to this power supply, but the corsair website told me I was blocked for security reasons…?

Let’s start with a short comment on the mainboard. It states that it supports a max of 32 GB of RAM on the German website, but claims 64 GB max on the English version. Weird.

The machine currently looks like this:

A picture of an open PC case. In it are two chambers. The lower one contains a power supply alongside a nest of cables. The model Corsair VS350 is noted on the side of the PSU. In the upper chamber is a brown mainboard, topped by a horizontal, low profile cooler in the proud brown and beige colors of Noctua.

So how to reuse this somewhat older hardware? Both the mainboard and the CPU are still alright. My use case for the system would be as a Ceph storage cluster node. If you’re interested in my storage setup, I’ve written about Ceph and my specific setup here. My current goal is splitting my Homelab into many smaller machines, mostly Raspberry Pis, for the sake of having high availability. I’ve currently already got one Odroid H3 serving as a Ceph node with a single HDD and SSD. I like it, as it’s pretty light on power consumption with the very efficient Intel Celeron N5105 at 10W TDP. And I had already decided to get two more of those, to replace my current x86 main machine serving two Ceph VMs with one HDD and one SSD each, behind a 1Gbps NIC.

On CPUbenchmark.net, the H3’s CPU is 25% faster and has a 25W lower TDP. It’s also 6 years newer than the AMD CPU. Also, the A10 uses the rather sad Excavator architecture.

For some measurements, I connected the machine to a smart power plug and booted it off a USB stick. The results were pretty sobering.

  • The A10-9700E eats 25W at idle, sitting at the command prompt of an Arch install USB stick
  • When fully loaded with stress --cpu 4, it goes up to 50W

On the bright side: The low profile Noctua NH-L9a-AM4 can easily cool the A10 at about 45 degrees C even with stress --cpu 4.

My only H3 is currently deployed as a Ceph node, so I can’t easily plug it into a separate power plug and measure it. But considering that it’s six years younger and an embedded class CPU, I expect it to come pretty close to the 10W TDP. The Odroid website claims about 1W - 9W idle and up to 18W under load. Which is still way lower than the 25W at which the A10 idled.

In addition, I would need a new PSU for the A10, as the current one just doesn’t sound very good anymore. It was cheap to begin with, and then ran non-stop for about three years.

But there are advantages to reusing the A10 and only buying one additional H3. First, it would save me about 100 bucks, when taking the new PSU for the A10 into account. Second, it has a proper PSU, with a lot of SATA power cables. And the Mainboard has four SATA ports, and multiple PCIe Gen3 ports for more SATA cards. The RAM can also be changed out, and it supports up to 64GB. So in theory, I would be able to connect a lot of disks to this thing. A lot more than the two that can be connected to the H3 before you have to go SATA port multiplier. And then there would still be the problem of powering more than two SATA disks, as the H3 only has two power connections and is itself supplied by a power brick, not a proper PSU.

Finally, there’s the environmental aspect. Instead of buying a new thing, almost none of which is upgradeable at all, I could reuse old hardware that would go into a landfill (well, some electronics recycling more likely) otherwise.

I must admit that, due to the power consumption of the A10, I’m still undecided.